<template>
  <!-- 买点书练习 -->
  <!-- 目标: 把数据铺设到页面上, 当用户点击买书按钮, 书籍数量增加1, 并且要计算累计的和 -->
  <div>
    <p>请选择你要购买的书籍</p>
    <ul>
      <li v-for="(item, index) in arr" :key="index">
        <span>{{ item.name }}</span>
        <button @click="buy(index)">买书</button>
      </li>
    </ul>
    <table border="1" width="500" cellspacing="0">
      <tr>
        <th>序号</th>
        <th>书名</th>
        <th>单价</th>
        <th>数量</th>
        <th>合计</th>
      </tr>
      <tr v-for="(item, index) in arr" :key="index">
        <td>{{ index + 1 }}</td>
        <td>{{ item.name }}</td>
        <td>{{ item.price }}</td>
        <td>{{ item.count }}</td>
        <td>{{ item.price * item.count }}</td>
      </tr>
    </table>

    <p>总价格为:{{ money }}元</p>
  </div>
</template>

<script>
export default {
  data() {
    return {
      arr: [
        {
          name: "水浒传",
          price: 107,
          count: 0,
        },
        {
          name: "西游记",
          price: 192,
          count: 0,
        },
        {
          name: "三国演义",
          price: 219,
          count: 0,
        },
        {
          name: "红楼梦",
          price: 178,
          count: 0,
        },
      ],
      add: "",
      sum: "",
    };
  },
  methods: {
    buy(ind) {
      this.arr[ind]["count"]++;
    },
  },
  computed: {
    money() {
      return this.arr.reduce((sum, item) => {
        console.log(item["name"]);
        console.log(item["price"]);
        console.log(item["count"]);
        //console.log(item["price"] == item.price);
        return (sum += item["price"] * item["count"]);
      }, 0);
    },
  },
};
</script>

<style></style>
